A mechanical joint may be provided as a structural interface between two elongated structural sections when it is, otherwise, not practical to provide or construct a continuous section thereof. Examples of elongated structural sections to which the present invention is applicable include cylindrical sections of substantially rigid thermal insulations, relatively flat sections of substantially rigid insulations, thermally elongatable or otherwise movable structural walls, panels, pavements, and decking, and the like. Typically, there are certain manufacturing, installation and/or environmental constraints which necessitate using a sectioned design as opposed to a continuous design. For example, there is often a limit to the length that the elongated section may be constructed in place. Such is the case in the construction of sections formed from a construction material such as concrete which must be finished and/or shaped before the material dries or sets in place.
In other applications, the elongated section(s) may have a tendency to elongate or contract due to thermal conditions. Thus, expansion room between sections must be provided. In this regard, it is often advantageous to minimize the length of the sections so as to minimize the potential elongation and the structural stresses which can be associated with such elongation. Further, flexible mechanical joints may be provided as the structural interface between the two movable elongated sections so as to absorb the movement between the two sections and to minimize the stresses generated in the sections as a result of such movement. The flexible mechanical joint also functions to fill the gap between the sections and to provide some uniformity at interface of the two sections.
A thermal insulation system may be provided on a product pipeline to maintain the temperature of the product transported therethrough. The insulation system may function to maintain the temperature of the transported fluid below the temperature of the external environment, such as in the case of the transportation of crude oil, natural gas, or petroleum products such as LPG or benzene. In the alternative, the insulation system may function to maintain the temperature of the transported fluid above the temperature of the external environment. Such an insulation system is provided on steam lines and also on some hydrocarbon pipelines such as, for example, subsea hydrocarbon pipelines.
Pipeline insulation systems suitable for low or high temperature applications come in a variety of forms and may utilize a variety of insulation materials. Typically, the primary properties considered in selecting the insulation material are the material's resistance to heat transfer and its cost. In some applications, it may also be desirable to provide insulation systems having high structural rigidity and a high compressive strength. This is particularly desirable in the application of insulation on subsea hydrocarbon applications wherein the insulation system is subjected to high hydrostatic pressures. Accordingly, the substantially rigid insulation system should have a compressive strength sufficiently high to withstand the stresses created by such hydrostatic pressures. In this regard, insulation made of a syntactic composite and having a compressive strength in excess of about 3000 psi has proven effective.